Glass fiber sight rib for firearm barrels having an outer jacket of glass fibers



G. R. SNYDER ETAL GLASS FIBER SIGHT RIB FOR FIREARM BARRELS HAVING AN OUTER JACKET OF GLASS FIBERS Flled May 19, 1961 Get. 22, 1963 INVENTORSI GEORGE R. SNYDER JOSEPH W. SILVA ATTORNEY 3,107,450 GLASS FHBER SITGHT REE FGR FEREARM BARRELS HAVENG AN OUTER .lACK T fil GLASS WEEKS George R. Snyder, Woodbridge, and .loseph W. Silva,

New Haven, Conn, assignors to Glin Mathieson @hemi= cal Corporation, a corporation of Virginia Filed May i9, i961, fier. No. llLlElS' 13 Claims. (til. 42-76) This invention relates to firearms and more specifically to a gun sight applicable to shotguns primarily, but useful also in other types of firearms. I

Shotguns are commonly provided with a steel sight rib extending down a steel barrel or between barrels of a double barrel gun; this arrangement in the heavier gauges as a rule is rather massive in comparison with rifles of the small arms type. Because of certain disadvantages associated with a heavy firearm of any type, there has been a trend toward lightweight constructions such as that of US. Patent No. 2,847,786, granted August 19, 1958, relating to a composite firearm barrel formed of a relatively thin metal liner and an outer jacket of fibre glass reinforced plastic. It is desirable, too, that such lightweight barrel be adapted for the provision of a sighting rib, but the adaptation heretofore of the conventional steel rib, for that matter, has always been a serious problem. In the manufacture of any type of gun, there has been the difliculty of including or attaching the rib in a way avoiding creating imbalance in the weapon, or differential thermal expansion and creation of strain unsymmetry in the barrel.

Therefore, one object of this invention is to provide a new and improved sight arrangement for firearms capable of minimizing and deflecting heat waves which rise from its barrel and which cause an atmospheric tremor disrupting the shooters line of sight. This may come about either by direct solar heating or after prolonged firing. In this respect, the invention provides a rib capable of remaining cool and giving a steady sight line. Another object is to provide a composite rib and barrel arrangement relatively free of problems arising from thermal expansion. Another object is to provide an improved barrel mounting a ventilated sight rib. A still further object is to provide a novel construction of ventilated rib giving maximum strength together with a minimum increase in weight of the firearm. Still another object is to provide a rib structure characterized by economy and simplicity of manufacture and an aesthetically appealing neatness in appearance together with sturdiness and a reliable securement to the barrel. This is quite important where long usage of the firearm occurs under the most severe and abusive conditions. Another object is to provide an improved weight distribution in a firearm having a rib sight. Other objects will become apparent from a description of specific embodiments now believed to be preferred when taken in connection with the accompanying drawing wherein:

CF16. l is a side elevational view of a shotgun barrel showing a ventilated sight rib according to one embodiment of the present invention mounted thereon;

FIG. 2 is an enlarged cross-sectional view taken on line II-Il of FIGURE 1;

FIG. 3 is a side elevational view of a shotgun barrel according to another embodiment;

FlG. 4 is an enlarged cross-sectional view taken on line IVlV of FIGURE 3; and

FIG. 5 is an enlarged fragmentary view taken on line VV to show the sight mounting preferred for both of the embodiments described.

In accordance with this invention, the problems, arising from the common practice of providing guns, especially shotguns, with an added substantial mass in the form lid of a sight rib and of securing that mass against thermal elongation and contraction and against undesired detachment without undue bending stress on the barrel, are solved by provision of a novel barrel and rib construction and combination.

One feature of this invention is in the strong lightweight structure of the ventilated rib made preferably of a resinous heatinsulating material, such as an epoxy plastic, preferably, or nylon, or the high strength acetal resins known as Dclrin, at least part of which is reinforced with fibrous glass. This is advantageous especially in combination with the composite lightweight barrel disclosed in US. Patent No. 2,847,786. Another feature is the provision along the entire complemental length of the barrel and rib of a body of suitable heat-resistant resin or plastic in the form of a bedding layer between the rib and the barrel for aflixing the rib and barrel together. The resinous material contemplated for this layer is one of the high strength plastics, such as cured epoxy resins, capable of forming a strong heat-resistant connection between the barrel and rib structure, and yet one that can give enough to avoid fracture under impact. This layer can be derived from either or both of the barrel and rib, 'when inclusive of suitable adhesiveforming resin such as epoxy resin.

Bonding may be provided by an intervening layer of rubber-like compounds including the most heat-resistant silicone compounds or the like suitable adhesive.

The lightweight rib structure may be either of onepiece or two-piece construction to which is added a front sight by an attachment extending preferably through both the rib and the barrel structures. Any suitable light material is contemplated for the rib structure. The onepiece rib is preferably plastic reinforced by fabric lamination running from the arcuately shaped interlayer to the sighting plane, i.e. athwart the sighting plane where the edges of the fabric form hair-like minute extensions or fuzz providing a desired mat finish. The two-piece rib has a base strip similar to the one-piece construction but modified to form extending posts or rungs to which is attached a sight strip preferably of plastic or light metal, defined to be a metal such as aluminum or any of its suitable alloys. The plastic sight strip may advantageously be of laminar construction by inclusion of a transversely crumpled longitudinally taut piece of suitable fabric such as one of fibrous glass.

An integral combination of barrel and rib according to this invention may advnatageously be made of highest strength by extending some of the strands or fabric of the rib into the barrel and the outer strands or fabric of the barrel into the rib and then blocking the whole arrangement in a suitable mold to the desired shape. Transverse ventilation openings may then be milled or routed through the projecting rib structure. in this further modification of the FIGURES 1 and 2 embodiment the fibres extend as common to both the rib and the barrel. One way of achieving this is by providing a circumferential surplus of strands and/or fabric in the barrel and then pinching the surplus of strands and/or fabric on the barrel and thereby pinching all surplus to form the rib prior to or while applying the epoxy or other resinous binder to the barrel jacket. Another way is to wind the barrel jacket strands and/ or fabric about both the barrel liner and a rod insert positioned to form the core of the rib after which the wound assembly is pressed to at least a rough shape and impregnated with the binder.

At the muzzle preferably, there is provided a cross pin connection between the barrel and rib. The connection is of the type for resisting tensile strain which might be induced by whiplash at the loop of any vibration encountered. The extending enlarged end of this pin advanta 'eously can be formed as a front sight.

As a product of manufacture, there is thus provided a round longitudinally extending tubular gun barrel or the like body having an elongated rib structure of lightweight material overlying said body in spaced relationship, where in the structure has cross ventilations preferably, and also having a resinous heat-insulating layer overlying said body and underlying said structure and forming a permeating bond between said body and structure to secure them against separation.

In the embodiment of FIGURE 1 and FIGURE 2, receiver 9 mountsa gun barrel it having an outer fibre glass plastic bonded portion or jacket 11 and an inner liner portion or sleeve 12 of any suitable metal such as steel resistant to erosion by the propellant and/or projectile. Inasmuch as the jacket is relied upon to withstand the transistory stresses in tension during firing and resist bursting, this relatively thin sleeve 12 is contained by the jacket, made preferably of high strength strands of glass bonded together and to the sleeve in stress transmitting relationship as disclosed in aforementioned US. Patent No. 2,847,786. Mounted upon the topside of portion 11 by interlayer 21, sight rib 13 is made of a glass fabric reinforced epoxy plastic laminate assembled with its layers running athwart the si hting plane formed by surface 14 so as to provide by the frayed ends of the included strands 17 a mat finish to sighting surface 14. Between the solid breech end 13 and solid muzzle end 19, the rib strip 13 is slotted to provide cross ventilation openings 16 alternating with rib posts 15 which may be of any shape, such as the forwardly and reardly tapered diamond shape left when openings 16 are made preferably by milling from both sides of the strip 13 across the laminations. Oopposite'plane surface 14, which extends without interruption straight down the length of the strip suitably spaced from the barrel 10 along its length, is the base portion 20 cut arcuately not only along its length to fit the longitudinal taper of the barrel, but also arcuately from side to side to provide the concavity complementary to the topside of barrel lit for reception of the intervening layer 21 by which barrel 10 is bonded to rib structure 13.

In the embodiment of FIGURES 3 and 4, the receiver 9 mounts the gun barrel 10 having as before an outer jacket formed of glass fibres bonded together in mutual stress-transmitting relationship and also the liner 12 forming the projectile discharge bore. The rib structure is of two-piece construction consisting of sight rib 23 carried by base rib 33 which in turn is mounted on layer 31 applied to the jacket 11.

Rib 23 is a channel-shaped piece of suitable plastic such as nylon, Teflon, epoxy resin, or the like suitable resin grooved or knurled at 27 to provide an acceptable sight plane 24. The rib is preferably a length strip cut from an extrusion having surface finish 27 and inwardly canted flanges 34 and 35 forming a tapered groove for slidable but frictionally retained reception of the dovetail shaped posts protruding at spaced intervals from the base rib 33 between the solid rear and front ends 23 and 29. Rib 23 and its flanges 34- and 35 are sufficiently flexible to allow rib 23 to be snapped on posts 2-5 as well as to be slidably received in the longitudinal direction. This allows rib 23 to move locally between posts to allow impact absorbing deflection and recovery in the event of the rib being stuck there. This preserves the planar character of sight plane 24 and minimizes fracture and denting.

Base rib 33 like rib 13 of the first embodiment is of laminated structure with the fabric running upwardly from interlayer 31 into each of the dovetail shaped posts 25. Rib 23 may be of laminated structure so as to include a lengthwise running strip of stretched fabric, as one of fibre glass, crushed together transversely and ex tending straight longitudinally for utmost resistance to plastic deformation or fracture while permitting maximum fiexure under impact.

As in the previous embodiment, the assembly of FIG- URES 3 and 4 provides ventilation openings at 26.

The assembly of the first embodiment involves liner 1.2, tubular jacket 11, arcuate layer 21 and rib 13.

The assembly of the second embodiment involves liner l2, tubular jacket ll, arcuate layer 31, base rib 33 and sight rib 23.

Both the one-piece rib 13 and the base rib 33 are obtained advantageously from smooth surfaced laminated sheet stock having a thickness equal to the desired width of these parts measuring from left to right (FIGURES 2 and 4). Sight plane surfaces 14 and 24 are cut through the sheet straight. The opposite arcuate complex surfaces for seating on the connecting layers 21 and 31 and the barrel are milled to the desired shape. The sheet stock is advantageously selected to a width equal to the desired length of parts 13 and 33.

The whole assembly of barrel and rib structures is then coated with a colored layer as one of a compatible black resin or lacquer dried and/ or cured in place, providing a fine durable black gun finish for the resultant integral ribbed gun barrel.

Each embodiment illustrated is provided at the respective front or muzzle ends 19 and 29 with a front sight structure shown in detail in FIGURE 5 and having in each instance a ball or other suitably shaped sight 73. This is provided on one end of fastener or pin 74, the other end of which is threaded at 76 for threaded connection with the female threaded extension 72 extruded by drift pin from the metal liner 12. The pin has at its sight end any suitable enlargement such as the head or flange 75 for pressing on the assembled parts thereby forming a tension resisting connection to prevent separation in the event maximum transverse vibration is encountered at the pin connection.

This invention is especially advantageous in manufacture of lightweight arms comprising parts of suitable plastics and lightweight metals such as magnesium, aluminum, titanium, and their alloys suitable for the purpose.

It is to be understood that the rib structure may be of either the matted type, i.e., a solid non-ventilated rib, or of the preferred ventilated type. In all embodiments and modifications, at least the base part of the rib and the barrel are joined tenaciously with a non-metallic bond.

In the foregoing, what are now believed to be preferred embodiments of the invention are shown and described, but it is to be further understood that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed:

1. A firearm having a barrel and a rib sight, said sight comprising an elongated member of lightweight material extending substantially the length of said barrel and permanently secured throughout said length to an outer part of said barrel throughout all of an opposed part of said member by an intervening non-metallic bond disposed between said parts complemental to each other for tenaciously securing said sight and barrel together, at least said complemental bond and complemental parts comprising a resinous heat-insulating plastic material.

2. The firearm of claim 1 having a lightweight barrel.

3. The firearm of claim 2 wherein the barrel has an inner metallic bore-forming liner and an outer jacket formed of glass fibres bonded to each other, to said rib sight, and to said liner in mutual stressstransmitting relation by the plastic material, an epoxy resin.

4. The firearm of claim 3 wherein the sight rib is a one-piece fibre glass-epoxy laminate having on one side along its length a sight plane and on the opposite side an arcuate generally concave surface constituting the opposed part complemental to the outer part of the barrel, said laminate having its laminations running along its length from one of said sides, wherein the fibre ends are exposed, to the other and having ventilating openings extending between said sides transversely of said laminations and spaced along its length, said ends producing a mat finish along the sight plane.

5. The firearm of claim 3 wherein the structure is a two-piece composite sight rib consisting of a base member of glass-epoxy laminate with dovetail projections on one side along its length and on the opposite side an arcuate generally concave surface complemental to the outer part of the barrel, a sight member having on one side a sight plane and on the opposite side a groove along its length complemented to said projections whereby said sight member is slidably received over all of said projections with frictional retention, and metal fastening means extending through said members and into one portion of said barrel for detachably securing said members together against movement with respect to said portion.

6. A firearm having a lightweight barrel and an elongated sight structure having its length extending at least partially the length of said barrel and supported throughout said lenth at complemental parts of said barrel and structure permanently secured together by an intervening adhesive bond disposed between said complementary parts of said barrel and structure, at least said barrel and bond at said parts comprising a resinous heat insulating plastic material, said barrel having an inner metallic bore-forming liner and an outer jacket formed of glass fibres bonded to each other, to said structure, and to said liner in mutual stress-transmitting relation by a heat resistant and insulating resin, said structure being a one-piece rib consisting of a fibre glass-epoxy laminate having on one side along its length a sight plane and on the opposite side an arcuate generally concave surface forming ,said part of the structure complemental to said part of the barrel, said laminate having its laminations running along its length and from one of said sides to the other, said laminate having ventilating openings extending between said sides transversely of said laminations and spaced along the length of said rib, said firearm including a metal fastening means extending through said rib and having ends one of which extends into said liner, said liner adjacent said one end being adapted .to form a connection for said end of the fastening means, the other end of which projects out of said rib as an enlargement defining a bead sight on said sight plane.

7. A firearm having a lightweight barrel and an elongated sight structure having its length extending at least partially the length of said barrel and supported throughout said length at complemental parts of said barrel and structure permanently secured together by an intervening adhesive bond disposed between said complementary parts of said barrel and structure, at least said barrel and bond at said parts comprising a resinous heat insulating plastic material, said barrel having an inner metallic bore-forming liner and an outer jacket formed of glass fibres bonded to each other, to said structure, and to said liner in mutual stress-transmitting relation by a heat resistant and insulating resin, said firearm including a metal threaded fastener through said structure, an internally threaded outward protrusion formed from said liner, said fastener having one end threadedly connected to said protrusion and the other end projecting as an enlargement bearing against the outside of said structure.

8. A firearm having a lightweight barrel and an elongated sight structure having its length extending at least partially the length of said barrel and supported throughout said length at complemental parts of said barrel and structure permanently secured together by an intervening adhesive bond disposed between said complementary parts of said barrel and structure, at least said barrel and bond at said parts comprising a resinous heat insulating plastic material, said barrel having an inner metallic bore-forming liner and an outer jacket formed of glass fibres bonded to each other, to said structure, and to said liner in mutual stress-transmitting relation by a heat resistant and insulating resin, said structure being a two-piece composite rib consisting of a base member of glass-epoxy laminate with dovetail projections on one side along its length and on the opposite side an arcuate generally concave surface fonning said structure part complemental to said part of the barrel, a sight member having on one side a sight plane and on the opposite side a groove along its length complemental to said projections whereby said sight member is slideably received over all of said projections with frictional retention, and metal fastening meansextending through said members and into a portion of said barrel for detachably securing said member and barrel together against movement at said portion, said liner having adjacent one of its ends a directly threaded connection for an end of the fastening means, the other end of which projects as an enlargement bearing against said one side of the sight member.

9. A firearm having a barrel and an elongated sight structure extending down substantially the full length of said barrel, said structure consisting of a base portion and a rib sight portion supported by said base portion in spaced laterally offset relationship with respect to an outer surface part of said barrel, at least said sight rib portion being of lightweight material such as resinous plastic and light metal, and said part of said barrel and said base portion comprising reinforcing fibres and an included body of heat-resistant heat-insulating resinous plastic material binding said fibres in stress-transmitting relation.

10. The firearm of claim 9 wherein the body and at least the outer surface part of the barrel and the base portion are one piece of epoxy resin adhered to fibres formed of glass.

11. The firearm of claim 10 wherein both the outer surface part of the barrel and all said structure are formed of one piece including glass fibres bonded to each other by the body of epoxy resin.

12. In the firearm of claim 9, a sight portion of nylon tongue and groove connected slidably to posts of a ven- Itilated base portion, and fastened against sliding by another connection.

13. In the firearm of claim 9, a sight portion of light metal tongue and groove connected slidably to posts of a ventilated base portion and fastened against sliding by another connection.

References Cited in the file of this patent UNITED STATES PATENTS 2,030,312 Mossberg Feb. 11, 1936 2,431,991 Crowe Dec. 2, 1947 2,822,616 Gangl Feb. 11, 1958 2,847,786 Hartley et al. Aug. 19, 1958 2,869,271 Berg Jan. 20, 1959 2,935,913 Wilson May 10, 1960 

9. A FIREARM HAVING A BAREL AND AN ELONGATED SIGHT STRUCTURE EXTENDING DOWN SUBSTANTIALLY THE FULL LENGTH OF SAID BARREL, SAID STURCTURE CONSISTING OF A BASE PORTION AND A RIB SIGHT PORTION SUPPORTED BY SAID BASE PORTION IN SPACED LATERALLY OFFSET RELATIONSHIP WITH RESPECT TO AN OUTER SURFACE PART OF SAID BARREL, AT LEAST SAID SIGHT RIB 